1. Field
The present disclosure relates to technology for encrypting and decrypting a message, and more particularly, to identifier (ID)-based encryption and decryption methods and apparatuses for the methods.
2. Discussion of Related Art
Recently, ID-based cryptography is newly attracting attention in the big data trend and environments of the Internet of Things. Also, with the advent of various security issues in cloud environments, a need for use of ID-based cryptography is increasing, and in particular, there is a need for ID-based cryptography that can be applied not to existing personal computers (PCs) or server environments but to small terminals such as mobile terminals. However, existing ID-based cryptography mostly employs pairing, thus involving too much calculation and being too complex to be applied to small terminals, such as a mobile terminal that is a client terminal. To solve this problem, a method employing a lattice has been introduced. The method employing a lattice shows excellent calculation performance, but has a drawback in that the sizes of parameters such as a public key, a ciphertext, etc. are too large.